RufusAtticus

And what genetic markers are those? Probably mtDNA or Y-DNA. Any autosomal markers?

ps418

I'm might be misunderstanding the question. . . but I think some of the microsatellite data referenced by the Risch article are based on autosomal microsatellite polymorphisms. Rosenberg et al (2002) used autosomal microsatellites also, and their analysis produces the same set of genetic clusters corresponding to continental groups (Genetic Structure of Human Populations, Science 298, pp. 2381-2385).

RufusAtticus

ps418,

Did their methods reveal any private alleles (alleles present in only one population)? Were any of them fixed?

Do they distinguish between "race" and "ethnicity?"

~~RvFvS~~

ps418

Rufus,

You'd really have to read the articles for yourself. My understanding in this area is pretty cursory, and I'm liable to get it wrong.

At the risk of being wrong, though, my understanding is that, yes, there are population-specific alleles. Whether they are fixed, or how many of them are fixed, I dont know.

In the Rosenberg article, they do not use the word race at all. They refer to "self-reported ancestry" instead.

RufusAtticus

Will do.

ps418

Though slightly off-topic, I managed to falsify an assumption of mine while looking for information on this topic. Also included at the bottom of this post are some free papers relating to the original topic of this thread.

My assumption had been that humans are exceptionally genetically homogenous, compared to chimps and other mammals, due to passing through a recent population bottleneck. After reading a few papers on the subject, it now seems that this assumption was faulty, and that on many measures of autosomal genetic diversity, humans are actually quite a bit more diverse than their nearest relatives, and are pretty diverse compared to other mammals as well.

According to Makarieva (2001), the average protein-coding loci heterozygosity for 321 mammalian species is 5%, with a range from 0% to 22%. According to Takahata (1995), the protein coding loci heterozygosity of humans is 10-14%, well above the mean value for mammals, and substantially higher for chimps (like 7%, IIRC). Wise et al's paper (1997) appears to confirm that humans are also more genetically diverse than chimps with respect to short tandem repeat (STR) polymorphisms, and mentions other research showing the same pattern for minisatellite heterozygosities.

Is there an concensus explanation for why mtDNA would show less diversity in humans compared to chimps, when autosomal DNA shows the opposite pattern?

<a href="http://www.icb.ufmg.br/~lgb/pg/pdf/jorde2000ajhg.pdf" target="_blank">Jorde LB, Watkins WS, Bamshad MJ, Dixon ME, Ricker CE, Seielstad MT, Batzer MA (2000) The distribution of human genetic diversity: a comparison of mitochondrial, autosomal, and Y-chromosome data. Am J Hum Genet 66:979-88.</a> PDF file.

<a href="http://mbe.library.arizona.edu/data/1997/1407/3wise.pdf" target="_blank">CA Wise, M Sraml, DC Rubinsztein, S Easteal, 1997. Comparative nuclear and mitochondrial genome diversity in humans and chimpanzees. Mol Bio and Evo 14, pp. 707-716. </a> PDF file.

<a href="http://www.sciencemag.org/cgi/content/full/298/5602/2381?" target="_blank">Rosenberg, et al., 2002. Genetic Structure of Human Populations. Science 298: 2381-2385 </a> Free full text.

<a href="http://www.sciencemag.org/cgi/content/full/293/5529/489" target="_blank">Stephens et al., 2001. Haplotype Variation and Linkage Disequilibrium in 313 Human Genes Science 293, pp. 489-493.</a>

<a href="http://www.nature.com/cgi-taf/DynaPage.taf?file=/hdy/journal/v87/n1/abs/6888990ab.html" target="_blank">Makarieva, A.M., 2001. Variance of protein heterozygosity in different species of mammals with respect to the number of loci studied. Heredity 87, pp. 41-51. </a>

Takahata, N., 1995. A Genetic Perspective on the Origin and History of Humans. Annu. Rev. Ecol. Syst. 26, pp. 343-372.

Anti-Creedance Front

Even though I am a humanist, I am opposed to racial interbreeding. No, I don't go around harassing mixed race people, but I think we should preserve our heritage as much as possible. I suppose this study could support the argument that genes don't come into play in race, and when you breed with someone of another race, you are actually mixing races.

bluefugue

Well, personally speaking my racial heritage means fuck-all to me, so I say mix it up! Also, I am attracted to women who are half-Asian, half-Caucasian...

Vorkosigan

What heritage? Bad eyes? Diabetes? Tendency to fat? Bow-leggedness? Susceptibility to skin cancer? That's my heritage, and I don't want my kids to have any of it.

What counts as race-mixing? I, a Polish-Italian with genes from all over the Old World, married a Taiwanese with genes from Asia and Polynesia and Europe. Isn't everyone already mixed-race? How would you define it?

Skydancer

Well, ignoring the fact that the whole point of this thread is that there is little difference between the so-called races of humanity, why wouldn't you want to mix them? In animal husbandry, the process is called hybrid vigor - the descendants of a cross like that have all the dominant traits and few of the recessives. 'Preserving your genetic heritage' also has a name in animal husbandry. It's called 'inbreeding'....